You should only keep them in pairs because this is the way they breed naturally. They mate for life and will only take a new mate if their old mate died.

People colony breeding them are doing for profit and are damaging the species while their at it.

In the wild coturnix mate in pairs or very small coveys but after we interfered for several thousand years now not only can domestic coturnix males mate large groups of females....All of the birds are also completely lacking in wild instinct. They can't hatch their own eggs (because of improper breeding this is happening right now to button quail) They don't even try to evade predators a raccoon can grab them one after the other, in fact they'll walk right up to it. In short people captive breeding them anyway they felt like doing it, created a fat stupid bird that has no natural or wild instincts left. I don't want to see that happen to button quail even though it already is starting to.

Any of the sites below is a good source of info on properly raising buttons. Every link here will mention their monogamous habits.